Kamloops
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kamloops clear sky chart from 2005-11-06 to 2024-11-04.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	7% 8% 3 8% 6% 6% 6% 5% 7% 8% 38%	105382
	Night	7% 10% 4 9% 6% 6% 6% 5% 6% 7% 33%	102210
Transparency	Day	41% 12% 17% 19% 9% 2	105137
	Night	45% 12% 17% 17% 8% 1	102101
Seeing	Day	13% 17% 28% 25% 13% 3	15678
	Night	13% 12% 27% 30% 16% 2	23952

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	8% 17% 6% 13% 8% 7% 6% 5% 6% 6% 17%	2219
	11th to 20th	Day	8% 14% 4 10% 8% 6% 6% 4 6% 7% 25%	2330
	21st to end	Day	8% 16% 6% 14% 8% 8% 6% 5% 6% 6% 17%	2794
February	1st to 10th	Day	8% 14% 6% 12% 7% 6% 6% 4 6% 6% 24%	1567
	11th to 20th	Day	5% 13% 4 10% 6% 7% 6% 5% 7% 7% 29%	1665
	21st to end	Day	4 11% 5% 12% 7% 9% 6% 5% 7% 7% 25%	1508
March	1st to 10th	Day	3 10% 5% 11% 7% 7% 7% 7% 8% 10% 26%	3138
	11th to 20th	Day	2 8% 3 8% 6% 7% 7% 5% 7% 8% 40%	3381
	21st to end	Day	5% 10% 4 10% 8% 7% 7% 5% 7% 7% 30%	4089
April	1st to 10th	Day	5% 14% 5% 10% 6% 7% 7% 6% 7% 9% 24%	2280
	11th to 20th	Day	6% 12% 4 10% 8% 6% 6% 5% 6% 9% 28%	2257
	21st to end	Day	7% 10% 4 9% 7% 7% 6% 5% 8% 8% 29%	2660
May	1st to 10th	Day	6% 8% 3 7% 6% 5% 6% 4 5% 8% 42%	4420
	11th to 20th	Day	8% 8% 3 8% 6% 5% 5% 5% 9% 12% 32%	4377
	21st to end	Day	13% 14% 4 10% 6% 5% 6% 4 6% 7% 24%	4867
June	1st to 10th	Day	13% 8% 3 7% 5% 6% 6% 5% 7% 8% 31%	3019
	11th to 20th	Day	13% 9% 3 8% 8% 6% 7% 5% 7% 7% 25%	3040
	21st to end	Day	8% 6% 3 8% 7% 6% 5% 5% 6% 8% 40%	3040
July	1st to 10th	Day	4 3 1 4 3 3 4 3 5% 7% 63%	4846
	11th to 20th	Day	3 2 1 3 3 3 4 3 5% 6% 68%	4690
	21st to end	Day	4 3 2 4 3 4 5% 4 7% 9% 57%	4790
August	1st to 10th	Day	2 2 1 4 3 3 4 4 7% 9% 60%	4401
	11th to 20th	Day	3 3 1 5% 4 4 6% 6% 8% 11% 49%	4282
	21st to end	Day	8% 4 2 5% 4 4 5% 4 7% 9% 49%	4304
September	1st to 10th	Day	6% 5% 1 6% 5% 4 5% 3 5% 8% 53%	2280
	11th to 20th	Day	9% 7% 3 6% 6% 5% 6% 3 5% 8% 43%	2280
	21st to end	Day	10% 8% 2 7% 5% 6% 5% 4 8% 8% 37%	2039
October	1st to 10th	Day	7% 6% 3 8% 5% 6% 5% 4 6% 9% 43%	3180
	11th to 20th	Day	10% 11% 4 8% 5% 4 5% 4 5% 7% 37%	3082
	21st to end	Day	7% 10% 4 8% 6% 5% 5% 5% 7% 10% 34%	3101
November	1st to 10th	Day	10% 13% 3 11% 8% 7% 7% 4 5% 6% 27%	1554
	11th to 20th	Day	8% 11% 4 9% 8% 5% 6% 5% 6% 8% 30%	1520
	21st to end	Day	9% 12% 4 11% 8% 9% 7% 6% 6% 7% 21%	1399
December	1st to 10th	Day	6% 14% 5% 12% 9% 9% 7% 5% 6% 5% 23%	1330
	11th to 20th	Day	5% 13% 6% 17% 10% 7% 6% 6% 6% 6% 18%	1499
	21st to end	Day	6% 11% 5% 12% 9% 9% 8% 6% 8% 8% 18%	2154
January	1st to 10th	Night	11% 18% 6% 14% 8% 8% 6% 4 5% 6% 14%	4726
	11th to 20th	Night	7% 15% 7% 13% 8% 7% 6% 5% 6% 7% 19%	4565
	21st to end	Night	6% 14% 6% 15% 9% 8% 7% 5% 6% 6% 17%	4862
February	1st to 10th	Night	8% 16% 6% 13% 8% 7% 6% 5% 6% 7% 19%	2610
	11th to 20th	Night	6% 13% 4 10% 6% 6% 6% 5% 5% 7% 32%	2402
	21st to end	Night	4 12% 5% 13% 8% 5% 7% 6% 6% 7% 26%	1945
March	1st to 10th	Night	3 11% 4 8% 6% 6% 7% 7% 7% 9% 32%	3736
	11th to 20th	Night	2 7% 3 7% 5% 5% 6% 4 7% 8% 46%	3596
	21st to end	Night	6% 9% 4 9% 7% 7% 6% 5% 6% 8% 33%	3564
April	1st to 10th	Night	5% 10% 3 9% 6% 6% 6% 5% 6% 8% 35%	1900
	11th to 20th	Night	4 10% 4 9% 7% 6% 7% 4 8% 9% 32%	1870
	21st to end	Night	6% 8% 3 7% 6% 6% 6% 5% 6% 8% 39%	1520
May	1st to 10th	Night	8% 8% 3 9% 7% 5% 6% 4 6% 7% 36%	2540
	11th to 20th	Night	9% 7% 3 7% 6% 6% 7% 5% 8% 9% 33%	2516
	21st to end	Night	12% 10% 4 9% 6% 6% 5% 5% 6% 8% 30%	2704
June	1st to 10th	Night	13% 6% 2 9% 5% 4 6% 5% 7% 9% 34%	1158
	11th to 20th	Night	12% 8% 3 8% 6% 6% 6% 6% 8% 8% 30%	1140
	21st to end	Night	5% 5% 2 8% 6% 7% 6% 4 6% 7% 43%	1140
July	1st to 10th	Night	6% 4 2 4 4 4 5% 4 5% 6% 56%	2110
	11th to 20th	Night	3 2 1 3 3 3 4 3 5% 7% 66%	2270
	21st to end	Night	4 3 2 5% 4 4 4 4 5% 8% 58%	2762
August	1st to 10th	Night	2 3 1 5% 4 5% 5% 6% 7% 8% 54%	2529
	11th to 20th	Night	3 3 2 6% 5% 5% 6% 5% 8% 9% 47%	2544
	21st to end	Night	9% 5% 2 5% 4 4 4 4 7% 8% 48%	3370
September	1st to 10th	Night	5% 4 1 6% 4 4 3 4 6% 6% 56%	1900
	11th to 20th	Night	7% 5% 2 6% 5% 4 4 3 6% 9% 48%	1900
	21st to end	Night	8% 7% 3 7% 4 5% 4 4 6% 8% 44%	2138
October	1st to 10th	Night	9% 7% 2 7% 6% 5% 5% 4 6% 8% 42%	3800
	11th to 20th	Night	8% 9% 4 8% 5% 4 5% 4 6% 8% 38%	3852
	21st to end	Night	7% 9% 4 10% 6% 5% 4 3 5% 8% 39%	4457
November	1st to 10th	Night	12% 13% 3 9% 7% 7% 6% 4 5% 6% 26%	2595
	11th to 20th	Night	8% 13% 5% 10% 8% 6% 7% 4 5% 6% 26%	2660
	21st to end	Night	9% 16% 4 11% 9% 7% 7% 5% 6% 6% 21%	2759
December	1st to 10th	Night	8% 13% 5% 11% 9% 7% 7% 5% 6% 8% 23%	2850
	11th to 20th	Night	10% 17% 7% 15% 8% 7% 6% 4 5% 5% 15%	3688
	21st to end	Night	6% 13% 4 11% 9% 9% 8% 5% 6% 7% 20%	5532

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	62% 15% 13% 8% 2	2219
	11th to 20th	Day	55% 11% 16% 10% 2 6%	2352
	21st to end	Day	60% 17% 14% 7% 2	2794
February	1st to 10th	Day	60% 11% 12% 11% 6% 1	1567
	11th to 20th	Day	51% 11% 17% 13% 7%	1674
	21st to end	Day	52% 14% 17% 12% 4 1	1508
March	1st to 10th	Day	45% 16% 17% 15% 6%	3138
	11th to 20th	Day	36% 13% 21% 26% 3	3381
	21st to end	Day	48% 14% 18% 12% 8%	4089
April	1st to 10th	Day	52% 16% 15% 13% 4	2280
	11th to 20th	Day	50% 12% 14% 15% 8% 1	2257
	21st to end	Day	49% 13% 16% 14% 7%	2660
May	1st to 10th	Day	37% 11% 15% 24% 11% 1	4420
	11th to 20th	Day	37% 15% 21% 22% 6%	4380
	21st to end	Day	53% 16% 16% 11% 3	4868
June	1st to 10th	Day	48% 12% 14% 14% 7% 4	3019
	11th to 20th	Day	54% 12% 14% 14% 6%	3040
	21st to end	Day	40% 11% 17% 19% 11% 2	3040
July	1st to 10th	Day	21% 7% 12% 22% 25% 14%	4772
	11th to 20th	Day	17% 7% 10% 26% 28% 12%	4609
	21st to end	Day	22% 7% 18% 27% 19% 6%	4639
August	1st to 10th	Day	19% 8% 14% 34% 23% 2	4384
	11th to 20th	Day	24% 10% 27% 28% 9% 2	4324
	21st to end	Day	31% 9% 24% 29% 7% 1	4303
September	1st to 10th	Day	30% 10% 16% 30% 12% 2	2280
	11th to 20th	Day	40% 10% 13% 24% 12% 2	2280
	21st to end	Day	42% 11% 20% 18% 9% 1	2039
October	1st to 10th	Day	38% 10% 23% 22% 7%	3180
	11th to 20th	Day	46% 9% 20% 21% 4	3082
	21st to end	Day	44% 12% 25% 17% 3	3101
November	1st to 10th	Day	57% 12% 13% 14% 5% 1	1554
	11th to 20th	Day	51% 14% 16% 14% 4 1	1520
	21st to end	Day	58% 14% 13% 11% 4	1399
December	1st to 10th	Day	61% 13% 13% 11% 2	1330
	11th to 20th	Day	58% 19% 13% 8% 3	1501
	21st to end	Day	54% 17% 17% 10% 2	2154
January	1st to 10th	Night	62% 15% 15% 7% 2	4726
	11th to 20th	Night	59% 10% 13% 9% 4 4	4605
	21st to end	Night	58% 17% 15% 7% 2	4862
February	1st to 10th	Night	61% 10% 11% 11% 6% 1	2610
	11th to 20th	Night	49% 11% 15% 17% 8% 1	2404
	21st to end	Night	52% 12% 17% 13% 6%	1945
March	1st to 10th	Night	40% 16% 17% 18% 9%	3736
	11th to 20th	Night	29% 13% 25% 27% 6%	3597
	21st to end	Night	45% 14% 16% 14% 11%	3564
April	1st to 10th	Night	43% 14% 20% 17% 5%	1900
	11th to 20th	Night	45% 12% 17% 16% 10%	1870
	21st to end	Night	39% 13% 16% 21% 10%	1520
May	1st to 10th	Night	41% 11% 14% 21% 12% 1	2540
	11th to 20th	Night	37% 15% 20% 21% 6%	2516
	21st to end	Night	45% 15% 20% 15% 5%	2704
June	1st to 10th	Night	44% 11% 16% 19% 7% 3	1158
	11th to 20th	Night	47% 11% 17% 18% 7%	1140
	21st to end	Night	37% 10% 19% 20% 12% 2	1140
July	1st to 10th	Night	28% 6% 12% 18% 27% 9%	2075
	11th to 20th	Night	17% 6% 11% 27% 31% 7%	2228
	21st to end	Night	24% 7% 14% 26% 17% 12%	2674
August	1st to 10th	Night	22% 8% 14% 32% 21% 3	2521
	11th to 20th	Night	27% 11% 23% 25% 12% 2	2568
	21st to end	Night	32% 9% 26% 23% 9% 1	3370
September	1st to 10th	Night	27% 10% 16% 30% 15% 2	1900
	11th to 20th	Night	33% 10% 17% 22% 15% 4	1900
	21st to end	Night	37% 12% 19% 18% 12% 2	2138
October	1st to 10th	Night	39% 9% 21% 23% 8%	3800
	11th to 20th	Night	43% 8% 19% 24% 6%	3852
	21st to end	Night	44% 7% 22% 23% 3	4457
November	1st to 10th	Night	56% 12% 13% 13% 5%	2595
	11th to 20th	Night	55% 12% 14% 12% 6% 1	2660
	21st to end	Night	60% 12% 15% 9% 4	2759
December	1st to 10th	Night	56% 11% 17% 12% 4	2850
	11th to 20th	Night	68% 11% 11% 7% 2	3685
	21st to end	Night	54% 15% 19% 10% 3	5532

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	16% 22% 27% 21% 6% 7%	180
	11th to 20th	Day	12% 17% 32% 25% 11% 3	180
	21st to end	Day	16% 20% 33% 20% 10% 2	198
February	1st to 10th	Day	14% 24% 40% 16% 6%	227
	11th to 20th	Day	13% 23% 30% 23% 10% 1	365
	21st to end	Day	10% 22% 33% 23% 9% 2	352
March	1st to 10th	Day	16% 24% 31% 19% 10%	460
	11th to 20th	Day	15% 23% 27% 21% 12% 2	460
	21st to end	Day	17% 25% 31% 14% 11% 1	506
April	1st to 10th	Day	20% 24% 27% 21% 7% 1	460
	11th to 20th	Day	18% 25% 27% 20% 9% 2	452
	21st to end	Day	14% 21% 35% 19% 9% 2	460
May	1st to 10th	Day	14% 22% 28% 28% 6% 2	463
	11th to 20th	Day	12% 13% 28% 29% 16% 3	488
	21st to end	Day	12% 13% 32% 25% 15% 3	557
June	1st to 10th	Day	17% 18% 32% 21% 10% 1	849
	11th to 20th	Day	17% 12% 30% 27% 10% 3	870
	21st to end	Day	11% 12% 25% 30% 19% 3	870
July	1st to 10th	Day	9% 10% 27% 32% 19% 3	738
	11th to 20th	Day	7% 14% 26% 31% 18% 4	644
	21st to end	Day	6% 7% 22% 39% 21% 6%	531
August	1st to 10th	Day	5% 8% 21% 34% 24% 9%	487
	11th to 20th	Day	8% 9% 23% 30% 22% 9%	477
	21st to end	Day	10% 13% 27% 29% 15% 7%	539
September	1st to 10th	Day	11% 13% 30% 25% 14% 7%	490
	11th to 20th	Day	13% 14% 24% 28% 16% 4	490
	21st to end	Day	15% 19% 28% 25% 11% 2	490
October	1st to 10th	Day	18% 15% 23% 24% 15% 4	490
	11th to 20th	Day	19% 20% 24% 21% 14% 2	449
	21st to end	Day	20% 19% 27% 22% 10% 2	330
November	1st to 10th	Day	19% 18% 34% 18% 11% 1	208
	11th to 20th	Day	18% 23% 25% 17% 13% 3	180
	21st to end	Day	17% 19% 30% 20% 9% 5%	180
December	1st to 10th	Day	11% 18% 19% 27% 20% 4	180
	11th to 20th	Day	17% 16% 34% 18% 12% 4	180
	21st to end	Day	12% 15% 32% 28% 11% 2	198
January	1st to 10th	Night	21% 15% 32% 21% 9% 1	850
	11th to 20th	Night	16% 11% 31% 30% 12% 1	810
	21st to end	Night	11% 12% 32% 29% 13% 2	836
February	1st to 10th	Night	18% 14% 32% 26% 8% 2	760
	11th to 20th	Night	11% 12% 30% 36% 11%	744
	21st to end	Night	12% 13% 29% 28% 17% 2	628
March	1st to 10th	Night	11% 16% 29% 27% 14% 2	760
	11th to 20th	Night	10% 16% 31% 28% 14% 1	760
	21st to end	Night	11% 16% 28% 28% 14% 3	836
April	1st to 10th	Night	11% 14% 27% 29% 16% 3	760
	11th to 20th	Night	10% 15% 30% 30% 14% 1	742
	21st to end	Night	9% 15% 31% 30% 13% 2	380
May	1st to 10th	Night	11% 11% 29% 30% 17% 2	380
	11th to 20th	Night	10% 6% 25% 39% 18% 2	374
	21st to end	Night	11% 9% 21% 35% 21% 2	411
June	1st to 10th	Night	14% 9% 30% 34% 11% 1	380
	11th to 20th	Night	13% 7% 31% 32% 15% 2	380
	21st to end	Night	8% 7% 26% 36% 21% 2	380
July	1st to 10th	Night	9% 5% 22% 41% 22% 1	370
	11th to 20th	Night	7% 7% 23% 37% 26% 1	368
	21st to end	Night	5% 3 18% 44% 27% 3	416
August	1st to 10th	Night	4 3 17% 36% 34% 6%	378
	11th to 20th	Night	5% 2 18% 36% 32% 7%	397
	21st to end	Night	9% 6% 21% 36% 26% 3	760
September	1st to 10th	Night	7% 9% 19% 35% 27% 3	760
	11th to 20th	Night	10% 6% 18% 29% 31% 6%	760
	21st to end	Night	14% 11% 24% 30% 18% 3	760
October	1st to 10th	Night	13% 9% 22% 34% 20% 2	760
	11th to 20th	Night	16% 11% 25% 28% 18% 2	760
	21st to end	Night	19% 14% 27% 26% 12% 2	836
November	1st to 10th	Night	20% 14% 28% 30% 7% 1	754
	11th to 20th	Night	19% 18% 26% 26% 11% 1	760
	21st to end	Night	19% 14% 30% 25% 10% 2	859
December	1st to 10th	Night	13% 12% 28% 31% 14% 2	950
	11th to 20th	Night	18% 15% 31% 28% 8%	1010
	21st to end	Night	18% 13% 32% 28% 8% 1	1123

Page generated at 2024-11-01 19:47:34. Version ac07

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